进气畸变下低速轴流压气机失速起始特性试验

Stall inception of low-speed axial-flow compressor with inlet distortion

关键词:  航空航天推进系统  压气机  进气畸变  失速起始  试验

Key words:  Aerospace propulsion system  Compressor  Inlet distortion  Stall inception  Experiment

摘要:

为探索进气畸变对压气机失速起始特性的影响,本文以一台双级低速轴流压气机为研究对象,对均匀进气和多种进气畸变形式下的失速起始特性进行了详细研究。进气畸变包括1×90°稳态单波、2×90°稳态双波和1×90°周向旋转单波3种形式,压气机转速为600 r/min和800 r/min。试验结果表明,在均匀进气和固定进气畸变条件下该压气机均表现为模态波式失速起始特征,而在旋转畸变时观察不到失速前扰动信号。均匀进气时,失速前20～30个转子旋转周期即可观察到模态波的存在,其传播速度等于42%转子转速,并诱导产生旋转失速团,而且在失速发展过程中,失速团旋转速度保持不变。稳态进气畸变时,也是由模态波诱导产生旋转失速,但在失速团发展过程中,失速团的旋转速度会发生变化。旋转进气畸变时,失速前检测不到42%转子转速的模态波扰动,也没有发现尖脉冲扰动。

Abstract:

Stall inception of a 2-stage low speed axial-flow compressor with both of uniform and distorted inlet flow was investigated.The inlet distortion has three kinds,including 1 × 90° single wave,2 × 90° double wave,and 1 × 90° rotating single wave.The results show that the stall inception of this compressor is modal-wave type in both uniform and fixed-distortion inlet flow,and neither of modal-wave and spike can be detected in rotating distortion inlet flow.First,the stall inception phenomenon with uniform inlet is studied when the rotor speed is of 600 r/min and 800 r/min,and modal wave disturbance can be found before stall occurs.In the developing process,speed of the stall cell does not change,and it equals to 42% of rotor speed.The result shows that variation of speed does not change the stall onset phenomenon.Second,the stall onset processes with different distortion equipments are inspected.The results show that the distortion may affect the characteristic of stall inception.In fixed screen experiment,the results reveal that the modal wave appears before stall.The early stall cell rotates fast,which will become full developed stall cell whose speed will steady after few rotations.The full developed stall cell in this fixed distortion is 43% of rotor speed,almost the same with the uniform inlet flow.